You know Orwell himself was a fairly radical leftist, at least in his youth? He fought in a Trotskyite group in the Spanish Civil War.

People read Animal Farm's denunciations of the founding of the USSR and confuse his anti-Soviet stance with an anti-socialist stance. He was disillusioned with the behavior of the Russian communists during the Spanish Civil War, which really turned him against them.

(The anti-fascist coalition was broadly anarchist, with a smattering of foreign, communist, socialist and other forces. Despite being <5% of the total coalition, the Russian communist government refused to provide material aid unless their forces were put in charge, which the coalition declined. Since the western governments (Britain, France, US) refused to help at all, the anti-fascist forces had no support, and were overwhelmed by Franco, ushering in decades of fascism in Spain.)